Объяснение:
Mr(H3PO4) = 1*3 + 31 + 16*4 = 98
W(H) = Ar(H) *n / Mr(H3PO4) *100% = 1*3 / 98 *100% = 3%
W(P)= Ar(P) *n / Mr(H3PO4) *100% = 31*1 / 98 *100% = 32%
W(O) = Ar(O) *n / Mr(H3PO4) *100% = 16*4 / 98 *100% = 65%
